Rep. Jared Polis, a gay father and Democrat from Colorado, was one of the first members of Congress to react publicly to the news that as many as four or five shots were fired outside the U.S. Capitol in Washington, D.C.

Polis spoke by phone to MSNBC, telling the network that he and 15 staffers and guests had locked themselves in his office on Capitol Hill, closing and locking doors and windows, pulling the blinds, and awaiting further instructions from Capitol police. Polis reiterated that he and his colleagues were only slowly obtaining information through emergency alert systems and news reports available inside the office.

At 3:02 p.m. Eastern, Polis tweeted that the situation had indeed been stabilized, and the order to shelter in place had been lifted.

New info via txt: The incident requiring staff to shelter in place has been stabilized. Additional information will follow.

At 3:04 p.m. Eastern, the Senate sergeant at arms reported that the lockdown had officially been lifted, roughly 40 minutes after the first shots were fired, according to The Washington Post's live blog. The sergeant at arms directed all at the Capitol to "resume normal activities."

Capitol police chief Kim Dine told reporters at a press conference around 3:30 p.m. Eastern that police believe the incident was isolated, and unrelated to any sort of terrorism. Dine confirmed that a black sedan reportedly driven by a female tried to ram a barricade near the White House, then led officers on a high-speed chase down that ended near the Capitol when a uniformed Secret Service officer exchanged gunfire with the vehicle. CNN and NBC both reported that the suspect was killed in the exchange, and that a child was safely recovered from the car, according to USA Today. Dine also said the suspect hit an officer and his squad vehicle with her car. He could not confirm the condition of the victim, but said he believed the injured officer was conscious and breathing.